Picosecond dynamics of cresyl violet H-aggregates adsorbed on SiO{sub 2} and SnO{sub 2} nanocrystallites
- Radiation Laboratory, University of Notre Dame, Notre Dame, Indiana 46556 (United States)
The H-aggregates of cresyl violet dye which are formed on the negatively charged SiO{sub 2} and SnO{sub 2} nanocrystallites, exhibit relatively short-lived excitonic singlet state with a lifetime of about 35 ps. The difference absorption maximum ({lambda}{sub max}=470 nm) is blue shifted compared to the corresponding singlet excited state of monomer ({lambda}{sub max}=515 nm). Time-resolved transient absorption measurements show that these dye aggregates are capable of injecting electrons from the triplet excited state into SnO{sub 2} nanocrystallites. The rate constant for heterogeneous electron transfer as measured from the formation of cation radical and electron trapping in SnO{sub 2} nanocrystallites was 2.0{times}10{sup 8}s{sup {minus}1}. {copyright} {ital 1996 American Institute of Physics.}
- OSTI ID:
- 285853
- Journal Information:
- Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 3 Vol. 105; ISSN JCPSA6; ISSN 0021-9606
- Country of Publication:
- United States
- Language:
- English
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